python数据分析

python:如何根据第4列来对一个6*6随机整数矩阵排序？

>>> import random
>>> matrix = [[random.randint(1,100) for _ in range(6)] for _ in range(6)]
>>> matrix
[[98, 70, 72, 85, 5, 47], [8, 34, 67, 37, 48, 86], [58, 41, 14, 86, 67, 59], [12, 95, 17, 43, 68, 51], [28, 60, 87, 9, 5, 65], [20, 74, 43, 29, 89, 26]]
>>> [matrix[i][3] for i in range(6)] #测试用
[85, 37, 86, 43, 9, 29]
>>> for i in range(5):
    for j in range(i+1,6):
        if matrix[i][3]>matrix[j][3]:
            matrix[i][3],matrix[j][3]=matrix[j][3],matrix[i][3]

            
>>> matrix
[[98, 70, 72, 9, 5, 47], [8, 34, 67, 29, 48, 86], [58, 41, 14, 37, 67, 59], [12, 95, 17, 43, 68, 51], [28, 60, 87, 85, 5, 65], [20, 74, 43, 86, 89, 26]]
>>> [matrix[i][3] for i in range(6)] #测试用
[9, 29, 37, 43, 85, 86]